<template>
  <div class="app-container">
  <!--查询表单-->
  <el-form :inline="true" class="demo-form-inline">

    <!-- 所属分类：级联下拉列表 -->
    <!-- 一级分类 -->
    <el-form-item label="课程类别">
      <el-select
        v-model="courseQuery.subjectParentId"
        placeholder="请选择"
        @change="subjectLevelOneChanged">
        <el-option
          v-for="subject in subjectOneList"
          :key="subject.id"
          :label="subject.title"
          :value="subject.id"/>
      </el-select>

      <!-- 二级分类 -->
      <el-select v-model="courseQuery.subjectId" placeholder="请选择">
        <el-option
          v-for="subject in subjectTwoList"
          :key="subject.id"
          :label="subject.title"
          :value="subject.id"/>
      </el-select>
    </el-form-item>

    <!-- 标题 -->
    <el-form-item>
      <el-input v-model="courseQuery.title" placeholder="课程标题"/>
    </el-form-item>
    <!-- 讲师 -->
    <el-form-item>
      <el-select
        v-model="courseQuery.teacherId"
        placeholder="请选择讲师">
        <el-option
          v-for="teacher in teacherList"
          :key="teacher.id"
          :label="teacher.name"
          :value="teacher.id"/>
      </el-select>
    </el-form-item>

    <el-button type="primary" icon="el-icon-search" @click="getList()">查询</el-button>
    <el-button type="default" @click="resetData()">清空</el-button>
  </el-form>

  <!-- 表格 -->
  <el-table
    :data="list"
    border
    fit
    highlight-current-row
    row-class-name="myClassList">

    <el-table-column
      label="序号"
      width="70"
      align="center">
      <template slot-scope="scope">
        {{ (page - 1) * limit + scope.$index + 1 }}
      </template>
    </el-table-column>

    <el-table-column label="课程信息" width="470" align="center">
      <template slot-scope="scope">
        <div class="info">
          <div class="pic">
            <img :src="scope.row.cover" alt="scope.row.title" width="150px">
          </div>
          <div class="title">
            <a href="">{{ scope.row.title }}</a>
            <p>{{ scope.row.lessonNum }}课时</p>
          </div>
        </div>

      </template>
    </el-table-column>

    <el-table-column label="创建时间" align="center">
      <template slot-scope="scope">
        {{ scope.row.gmtCreate.substr(0, 10) }}
      </template>
    </el-table-column>
    <el-table-column label="发布时间" align="center">
      <template slot-scope="scope">
        {{ scope.row.gmtModified.substr(0, 10) }}
      </template>
    </el-table-column>
    <el-table-column label="价格" width="100" align="center" >
      <template slot-scope="scope">
        {{ Number(scope.row.price) === 0 ? '免费' :
        '¥' + scope.row.price.toFixed(2) }}
      </template>
    </el-table-column>
    <el-table-column prop="buyCount" label="付费学员" width="100" align="center" >
      <template slot-scope="scope">
        {{ scope.row.buyCount }}人
      </template>
    </el-table-column>

    <el-table-column label="操作" width="150" align="center">
      <template slot-scope="scope">
        <router-link :to="'/course/info/'+scope.row.id">
          <el-button type="text" size="mini" icon="el-icon-edit">编辑课程信息</el-button>
        </router-link>
        <router-link :to="'/course/chapter/'+scope.row.id">
          <el-button type="text" size="mini" icon="el-icon-edit">编辑课程大纲</el-button>
        </router-link>
        <el-button type="text" size="mini" icon="el-icon-delete" @click="removeDataById(scope.row.id)">删除</el-button>
      </template>
    </el-table-column>
  </el-table>

  <!-- 分页 -->
  <el-pagination
    :current-page="page"
    :page-size="limit"
    :total="total"
    style="padding: 30px 0; text-align: center;"
    layout="total, prev, pager, next, jumper"
    @current-change="getList"
  />
  </div>
</template>

<script>
    import course from "@/api/edu/course"
    import teacher from "@/api/edu/teacher"
    import subject from "@/api/edu/subject"

    export default {
        data(){
          return{
            list:null,      //查询后接口返回的结果
            page:1,         //当前页面
            limit:10,       //每页记录数
            total:0,        //总记录数
            courseQuery:{}, //条件对象
            subjectOneList:[],
            subjectTwoList:[],
            teacherList:[]
          }
        },
      created() {
        this.getTeacherList()
        this.getList()
        this.getOneSubjectList()
      },
      methods:{
        resetData(){
          this.courseQuery={}
          this.getList()
        },
        //获取讲师列表
        getTeacherList(){
          course.getTeacherList()
            .then(response=>{
              this.teacherList=response.data.teachers
            })
        },
        //获取一级分类列表
        getOneSubjectList(){
          subject.getSubjectList()
            .then(response=>{
              this.subjectOneList=response.data.list
            })
        },
        //当点击一级分类时，触发change事件
        subjectLevelOneChanged(value){  //value就是一级分类的id
          for (let i = 0; i < this.subjectOneList.length; i++) {
            if (this.subjectOneList[i].id === value) {
              this.subjectTwoList = this.subjectOneList[i].children
              //this.courseQuery.subjectId = ''
            }
          }
        },
        //条件查询分页
        getList(page=1){
          this.page=page;
          course.getCourseListPage(this.page,this.limit,this.courseQuery)
            .then(response=>{
              //请求成功
              this.list=response.data.rows
              this.total=response.data.total
            })
            .catch(error=>{
              //请求失败
              console.log(error)
            })
        },
        //删除课程
        removeDataById(id){
          this.$confirm('此操作将永久删除该课程, 是否继续?', '提示', {
            confirmButtonText: '确定',
            cancelButtonText: '取消',
            type: 'warning'
          }).then(() => {
             course.removeCourseById(id)
              .then(response=>{
                this.$message({
                  type: 'success',
                  message: '删除成功!'
                })
                this.getList()
              })
          })
        }
      }
    }
</script>

<style scoped>
  .myClassList .info {
    width: 450px;
    overflow: hidden;
  }
  .myClassList .info .pic {
    width: 150px;
    height: 90px;
    overflow: hidden;
    float: left;
  }
  .myClassList .info .pic a {
    display: block;
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
  }
  .myClassList .info .pic img {
    display: block;
    width: 100%;
  }
  .myClassList td .info .title {
    width: 280px;
    float: right;
    height: 90px;
  }
  .myClassList td .info .title a {
    display: block;
    height: 48px;
    line-height: 24px;
    overflow: hidden;
    color: #00baf2;
    margin-bottom: 12px;
  }
  .myClassList td .info .title p {
    line-height: 20px;
    margin-top: 5px;
    color: #818181;
  }
</style>

